Summary of Significant Accounting Policies Concentration of Credit Risk (Details)	Dec. 31, 2012	Dec. 31, 2011
Percentage of accounts receivable total	66.00%	71.90%
Telvent [Member]
Percentage of accounts receivable	46.10%	46.20%
Duke [Member]
Percentage of accounts receivable	0.00%	15.70%
Enel [Member] [Member]
Percentage of accounts receivable	9.40%	0.00%
Eltel [Member]
Percentage of accounts receivable	1.30%	7.50%
Ebv Avnet [Member]
Percentage of accounts receivable	9.20%	2.50%